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UN-backed treaty banning most dangerous pesticides to come into force in May

UN-backed treaty banning most dangerous pesticides to come into force in May

An international treaty banning the world's most dangerous pesticides, industrial chemicals and hazardous by-products of combustion will enter into force on 17 May now that 50 countries have ratified the pact, the United Nations announced today.

The 2001 Stockholm Convention on Persistent Organic Pollutants (POPs) bans a dozen potentially lethal and deforming toxic substances, which travel through the environment far beyond their original source and endure for years or even decades.

“Of all the pollutants released into the environment every year by human activity, POPs are the most dangerous,” said Klaus Toepfer, Executive Director of the UN Environment Programme (UNEP) under whose auspices the treaty was negotiated. “For decades these highly toxic chemicals have killed and injured people and wildlife by inducing cancer and damaging the nervous, reproductive and immune systems. They have also caused uncounted birth defects," he added in a news release.

The 90-day countdown to the convention’s entry into force was triggered yesterday with France’s ratification. Canada was the first country to ratify, on 23 May 2001. The 12 POPs are aldrin, chlordane, DDT, dieldrin, endrin, heptachlor, mirex, toxaphene, polychlorinated biphenols (PCBs), hexachlorobenzene, dioxins and furans.

Most will be banned at once, but use of DDT for disease vector control under UN World Health Organization (WHO) guidelines is considered acceptable because it is still essential in many countries to control malaria transmission by mosquitoes. A Review Committee will regularly consider additional substances to be added to the list of those banned.

The Convention sets out control measures covering production, import, export, disposal, and use. It requires governments to promote the best available technologies and practices for replacing existing POPs while preventing development of new ones.

Every human carries traces of POPs, which circulate globally through a process known as the "grasshopper effect." POPs released in one part of the world can, through a repeated process of evaporation and deposit, be transported through the atmosphere to regions far away from the original source. Though not soluble in water, they are readily absorbed in fatty tissue, where concentrations can become magnified by up to 70,000 times the background levels. Fish, predatory birds, mammals and humans high up the food chain absorb the greatest concentrations. When they travel, POPs go with them.